diff --git a/synapse/events/snapshot.py b/synapse/events/snapshot.py index e895b1c450..11605b34a3 100644 --- a/synapse/events/snapshot.py +++ b/synapse/events/snapshot.py @@ -15,9 +15,30 @@ class EventContext(object): + __slots__ = [ + "current_state_ids", + "prev_state_ids", + "state_group", + "rejected", + "push_actions", + "prev_group", + "delta_ids", + "prev_state_events", + ] + def __init__(self): + # The current state including the current event self.current_state_ids = None + # The current state excluding the current event self.prev_state_ids = None self.state_group = None + self.rejected = False self.push_actions = [] + + # A previously persisted state group and a delta between that + # and this state. + self.prev_group = None + self.delta_ids = None + + self.prev_state_events = None diff --git a/synapse/replication/slave/storage/events.py b/synapse/replication/slave/storage/events.py index cbebd5b2f7..15c52774a2 100644 --- a/synapse/replication/slave/storage/events.py +++ b/synapse/replication/slave/storage/events.py @@ -86,6 +86,9 @@ class SlavedEventStore(BaseSlavedStore): _get_state_groups_from_groups = ( StateStore.__dict__["_get_state_groups_from_groups"] ) + _get_state_groups_from_groups_txn = ( + DataStore._get_state_groups_from_groups_txn.__func__ + ) _get_state_group_from_group = ( StateStore.__dict__["_get_state_group_from_group"] ) diff --git a/synapse/state.py b/synapse/state.py index cd792afed1..4520fa0415 100644 --- a/synapse/state.py +++ b/synapse/state.py @@ -55,12 +55,15 @@ def _gen_state_id(): class _StateCacheEntry(object): - __slots__ = ["state", "state_group", "state_id"] + __slots__ = ["state", "state_group", "state_id", "prev_group", "delta_ids"] - def __init__(self, state, state_group): + def __init__(self, state, state_group, prev_group=None, delta_ids=None): self.state = state self.state_group = state_group + self.prev_group = prev_group + self.delta_ids = delta_ids + # The `state_id` is a unique ID we generate that can be used as ID for # this collection of state. Usually this would be the same as the # state group, but on worker instances we can't generate a new state @@ -245,11 +248,20 @@ class StateHandler(object): if key in context.prev_state_ids: replaces = context.prev_state_ids[key] event.unsigned["replaces_state"] = replaces + context.current_state_ids = dict(context.prev_state_ids) context.current_state_ids[key] = event.event_id + + context.prev_group = entry.prev_group + context.delta_ids = entry.delta_ids + if context.delta_ids is not None: + context.delta_ids[key] = event.event_id else: context.current_state_ids = context.prev_state_ids + context.prev_group = entry.prev_group + context.delta_ids = entry.delta_ids + context.prev_state_events = [] defer.returnValue(context) @@ -283,6 +295,8 @@ class StateHandler(object): defer.returnValue(_StateCacheEntry( state=state_list, state_group=name, + prev_group=name, + delta_ids={}, )) with (yield self.resolve_linearizer.queue(group_names)): @@ -340,9 +354,24 @@ class StateHandler(object): if hasattr(self.store, "get_next_state_group"): state_group = self.store.get_next_state_group() + prev_group = None + delta_ids = None + for old_group, old_ids in state_groups_ids.items(): + if not set(new_state.iterkeys()) - set(old_ids.iterkeys()): + n_delta_ids = { + k: v + for k, v in new_state.items() + if old_ids.get(k) != v + } + if not delta_ids or len(n_delta_ids) < len(delta_ids): + prev_group = old_group + delta_ids = n_delta_ids + cache = _StateCacheEntry( state=new_state, state_group=state_group, + prev_group=prev_group, + delta_ids=delta_ids, ) if self._state_cache is not None: diff --git a/synapse/storage/events.py b/synapse/storage/events.py index 1a7d4c5199..ed182c8d11 100644 --- a/synapse/storage/events.py +++ b/synapse/storage/events.py @@ -497,7 +497,11 @@ class EventsStore(SQLBaseStore): # insert into the state_group, state_groups_state and # event_to_state_groups tables. - self._store_mult_state_groups_txn(txn, ((event, context),)) + try: + self._store_mult_state_groups_txn(txn, ((event, context),)) + except Exception: + logger.exception("") + raise metadata_json = encode_json( event.internal_metadata.get_dict() @@ -1543,6 +1547,9 @@ class EventsStore(SQLBaseStore): ) event_rows = txn.fetchall() + for event_id, state_key in event_rows: + txn.call_after(self._get_state_group_for_event.invalidate, (event_id,)) + # We calculate the new entries for the backward extremeties by finding # all events that point to events that are to be purged txn.execute( @@ -1582,7 +1589,66 @@ class EventsStore(SQLBaseStore): " GROUP BY state_group HAVING MAX(topological_ordering) < ?", (room_id, topological_ordering, topological_ordering) ) + state_rows = txn.fetchall() + state_groups_to_delete = [sg for sg, in state_rows] + + # Now we get all the state groups that rely on these state groups + new_state_edges = [] + chunks = [ + state_groups_to_delete[i:i + 100] + for i in xrange(0, len(state_groups_to_delete), 100) + ] + for chunk in chunks: + rows = self._simple_select_many_txn( + txn, + table="state_group_edges", + column="prev_state_group", + iterable=chunk, + retcols=["state_group"], + keyvalues={}, + ) + new_state_edges.extend(row["state_group"] for row in rows) + + # Now we turn the state groups that reference to-be-deleted state groups + # to non delta versions. + for new_state_edge in new_state_edges: + curr_state = self._get_state_groups_from_groups_txn( + txn, [new_state_edge], types=None + ) + curr_state = curr_state[new_state_edge] + + self._simple_delete_txn( + txn, + table="state_groups_state", + keyvalues={ + "state_group": new_state_edge, + } + ) + + self._simple_delete_txn( + txn, + table="state_group_edges", + keyvalues={ + "state_group": new_state_edge, + } + ) + + self._simple_insert_many_txn( + txn, + table="state_groups_state", + values=[ + { + "state_group": new_state_edge, + "room_id": room_id, + "type": key[0], + "state_key": key[1], + "event_id": state_id, + } + for key, state_id in curr_state.items() + ], + ) + txn.executemany( "DELETE FROM state_groups_state WHERE state_group = ?", state_rows diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py index b94ce7bea1..b1fbc4ffa5 100644 --- a/synapse/storage/prepare_database.py +++ b/synapse/storage/prepare_database.py @@ -25,7 +25,7 @@ logger = logging.getLogger(__name__) # Remember to update this number every time a change is made to database # schema files, so the users will be informed on server restarts. -SCHEMA_VERSION = 34 +SCHEMA_VERSION = 35 dir_path = os.path.abspath(os.path.dirname(__file__)) diff --git a/synapse/storage/schema/delta/35/state.sql b/synapse/storage/schema/delta/35/state.sql new file mode 100644 index 0000000000..0f1fa68a89 --- /dev/null +++ b/synapse/storage/schema/delta/35/state.sql @@ -0,0 +1,22 @@ +/* Copyright 2016 OpenMarket Ltd + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +CREATE TABLE state_group_edges( + state_group BIGINT NOT NULL, + prev_state_group BIGINT NOT NULL +); + +CREATE INDEX state_group_edges_idx ON state_group_edges(state_group); +CREATE INDEX state_group_edges_prev_idx ON state_group_edges(prev_state_group); diff --git a/synapse/storage/schema/delta/35/state_dedupe.sql b/synapse/storage/schema/delta/35/state_dedupe.sql new file mode 100644 index 0000000000..97e5067ef4 --- /dev/null +++ b/synapse/storage/schema/delta/35/state_dedupe.sql @@ -0,0 +1,17 @@ +/* Copyright 2016 OpenMarket Ltd + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +INSERT into background_updates (update_name, progress_json) + VALUES ('state_group_state_deduplication', '{}'); diff --git a/synapse/storage/state.py b/synapse/storage/state.py index ec551b0b4f..0730399b80 100644 --- a/synapse/storage/state.py +++ b/synapse/storage/state.py @@ -16,6 +16,7 @@ from ._base import SQLBaseStore from synapse.util.caches.descriptors import cached, cachedList from synapse.util.caches import intern_string +from synapse.storage.engines import PostgresEngine from twisted.internet import defer @@ -24,6 +25,9 @@ import logging logger = logging.getLogger(__name__) +MAX_STATE_DELTA_HOPS = 100 + + class StateStore(SQLBaseStore): """ Keeps track of the state at a given event. @@ -43,6 +47,15 @@ class StateStore(SQLBaseStore): * `state_groups_state`: Maps state group to state events. """ + STATE_GROUP_DEDUPLICATION_UPDATE_NAME = "state_group_state_deduplication" + + def __init__(self, hs): + super(StateStore, self).__init__(hs) + self.register_background_update_handler( + self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME, + self._background_deduplicate_state, + ) + @defer.inlineCallbacks def get_state_groups_ids(self, room_id, event_ids): if not event_ids: @@ -103,11 +116,8 @@ class StateStore(SQLBaseStore): state_groups[event.event_id] = context.state_group if self._have_persisted_state_group_txn(txn, context.state_group): - logger.info("Already persisted state_group: %r", context.state_group) continue - state_event_ids = dict(context.current_state_ids) - self._simple_insert_txn( txn, table="state_groups", @@ -118,20 +128,51 @@ class StateStore(SQLBaseStore): }, ) - self._simple_insert_many_txn( - txn, - table="state_groups_state", - values=[ - { + # We persist as a delta if we can, while also ensuring the chain + # of deltas isn't tooo long, as otherwise read performance degrades. + if context.prev_group: + potential_hops = self._count_state_group_hops_txn( + txn, context.prev_group + ) + if context.prev_group and potential_hops < MAX_STATE_DELTA_HOPS: + self._simple_insert_txn( + txn, + table="state_group_edges", + values={ "state_group": context.state_group, - "room_id": event.room_id, - "type": key[0], - "state_key": key[1], - "event_id": state_id, - } - for key, state_id in state_event_ids.items() - ], - ) + "prev_state_group": context.prev_group, + }, + ) + + self._simple_insert_many_txn( + txn, + table="state_groups_state", + values=[ + { + "state_group": context.state_group, + "room_id": event.room_id, + "type": key[0], + "state_key": key[1], + "event_id": state_id, + } + for key, state_id in context.delta_ids.items() + ], + ) + else: + self._simple_insert_many_txn( + txn, + table="state_groups_state", + values=[ + { + "state_group": context.state_group, + "room_id": event.room_id, + "type": key[0], + "state_key": key[1], + "event_id": state_id, + } + for key, state_id in context.current_state_ids.items() + ], + ) self._simple_insert_many_txn( txn, @@ -145,6 +186,47 @@ class StateStore(SQLBaseStore): ], ) + def _count_state_group_hops_txn(self, txn, state_group): + """Given a state group, count how many hops there are in the tree. + + This is used to ensure the delta chains don't get too long. + """ + if isinstance(self.database_engine, PostgresEngine): + sql = (""" + WITH RECURSIVE state(state_group) AS ( + VALUES(?::bigint) + UNION ALL + SELECT prev_state_group FROM state_group_edges e, state s + WHERE s.state_group = e.state_group + ) + SELECT count(*) FROM state; + """) + + txn.execute(sql, (state_group,)) + row = txn.fetchone() + if row and row[0]: + return row[0] + else: + return 0 + else: + # We don't use WITH RECURSIVE on sqlite3 as there are distributions + # that ship with an sqlite3 version that doesn't support it (e.g. wheezy) + next_group = state_group + count = 0 + + while next_group: + next_group = self._simple_select_one_onecol_txn( + txn, + table="state_group_edges", + keyvalues={"state_group": next_group}, + retcol="prev_state_group", + allow_none=True, + ) + if next_group: + count += 1 + + return count + @defer.inlineCallbacks def get_current_state(self, room_id, event_type=None, state_key=""): if event_type and state_key is not None: @@ -206,48 +288,99 @@ class StateStore(SQLBaseStore): def _get_state_groups_from_groups(self, groups, types): """Returns dictionary state_group -> (dict of (type, state_key) -> event id) """ - def f(txn, groups): - if types is not None: - where_clause = "AND (%s)" % ( - " OR ".join(["(type = ? AND state_key = ?)"] * len(types)), - ) - else: - where_clause = "" - - sql = ( - "SELECT state_group, event_id, type, state_key" - " FROM state_groups_state WHERE" - " state_group IN (%s) %s" % ( - ",".join("?" for _ in groups), - where_clause, - ) - ) - - args = list(groups) - if types is not None: - args.extend([i for typ in types for i in typ]) - - txn.execute(sql, args) - rows = self.cursor_to_dict(txn) - - results = {group: {} for group in groups} - for row in rows: - key = (row["type"], row["state_key"]) - results[row["state_group"]][key] = row["event_id"] - return results - results = {} chunks = [groups[i:i + 100] for i in xrange(0, len(groups), 100)] for chunk in chunks: res = yield self.runInteraction( "_get_state_groups_from_groups", - f, chunk + self._get_state_groups_from_groups_txn, chunk, types, ) results.update(res) defer.returnValue(results) + def _get_state_groups_from_groups_txn(self, txn, groups, types=None): + if types is not None: + where_clause = "AND (%s)" % ( + " OR ".join(["(type = ? AND state_key = ?)"] * len(types)), + ) + else: + where_clause = "" + + results = {group: {} for group in groups} + if isinstance(self.database_engine, PostgresEngine): + # The below query walks the state_group tree so that the "state" + # table includes all state_groups in the tree. It then joins + # against `state_groups_state` to fetch the latest state. + # It assumes that previous state groups are always numerically + # lesser. + sql = (""" + WITH RECURSIVE state(state_group) AS ( + VALUES(?::bigint) + UNION ALL + SELECT prev_state_group FROM state_group_edges e, state s + WHERE s.state_group = e.state_group + ) + SELECT type, state_key, event_id FROM state_groups_state + WHERE ROW(type, state_key, state_group) IN ( + SELECT type, state_key, max(state_group) FROM state + INNER JOIN state_groups_state USING (state_group) + GROUP BY type, state_key + ) + %s; + """) % (where_clause,) + + for group in groups: + args = [group] + if types is not None: + args.extend([i for typ in types for i in typ]) + + txn.execute(sql, args) + rows = self.cursor_to_dict(txn) + for row in rows: + key = (row["type"], row["state_key"]) + results[group][key] = row["event_id"] + else: + # We don't use WITH RECURSIVE on sqlite3 as there are distributions + # that ship with an sqlite3 version that doesn't support it (e.g. wheezy) + for group in groups: + group_tree = [group] + next_group = group + + while next_group: + next_group = self._simple_select_one_onecol_txn( + txn, + table="state_group_edges", + keyvalues={"state_group": next_group}, + retcol="prev_state_group", + allow_none=True, + ) + if next_group: + group_tree.append(next_group) + + sql = (""" + SELECT type, state_key, event_id FROM state_groups_state + INNER JOIN ( + SELECT type, state_key, max(state_group) as state_group + FROM state_groups_state + WHERE state_group IN (%s) %s + GROUP BY type, state_key + ) USING (type, state_key, state_group); + """) % (",".join("?" for _ in group_tree), where_clause,) + + args = list(group_tree) + if types is not None: + args.extend([i for typ in types for i in typ]) + + txn.execute(sql, args) + rows = self.cursor_to_dict(txn) + for row in rows: + key = (row["type"], row["state_key"]) + results[group][key] = row["event_id"] + + return results + @defer.inlineCallbacks def get_state_for_events(self, event_ids, types): """Given a list of event_ids and type tuples, return a list of state @@ -504,32 +637,150 @@ class StateStore(SQLBaseStore): defer.returnValue(results) - def get_all_new_state_groups(self, last_id, current_id, limit): - def get_all_new_state_groups_txn(txn): - sql = ( - "SELECT id, room_id, event_id FROM state_groups" - " WHERE ? < id AND id <= ? ORDER BY id LIMIT ?" - ) - txn.execute(sql, (last_id, current_id, limit)) - groups = txn.fetchall() - - if not groups: - return ([], []) - - lower_bound = groups[0][0] - upper_bound = groups[-1][0] - sql = ( - "SELECT state_group, type, state_key, event_id" - " FROM state_groups_state" - " WHERE ? <= state_group AND state_group <= ?" - ) - - txn.execute(sql, (lower_bound, upper_bound)) - state_group_state = txn.fetchall() - return (groups, state_group_state) - return self.runInteraction( - "get_all_new_state_groups", get_all_new_state_groups_txn - ) - def get_next_state_group(self): return self._state_groups_id_gen.get_next() + + @defer.inlineCallbacks + def _background_deduplicate_state(self, progress, batch_size): + """This background update will slowly deduplicate state by reencoding + them as deltas. + """ + last_state_group = progress.get("last_state_group", 0) + rows_inserted = progress.get("rows_inserted", 0) + max_group = progress.get("max_group", None) + + BATCH_SIZE_SCALE_FACTOR = 100 + + batch_size = max(1, int(batch_size / BATCH_SIZE_SCALE_FACTOR)) + + if max_group is None: + rows = yield self._execute( + "_background_deduplicate_state", None, + "SELECT coalesce(max(id), 0) FROM state_groups", + ) + max_group = rows[0][0] + + def reindex_txn(txn): + new_last_state_group = last_state_group + for count in xrange(batch_size): + txn.execute( + "SELECT id, room_id FROM state_groups" + " WHERE ? < id AND id <= ?" + " ORDER BY id ASC" + " LIMIT 1", + (new_last_state_group, max_group,) + ) + row = txn.fetchone() + if row: + state_group, room_id = row + + if not row or not state_group: + return True, count + + txn.execute( + "SELECT state_group FROM state_group_edges" + " WHERE state_group = ?", + (state_group,) + ) + + # If we reach a point where we've already started inserting + # edges we should stop. + if txn.fetchall(): + return True, count + + txn.execute( + "SELECT coalesce(max(id), 0) FROM state_groups" + " WHERE id < ? AND room_id = ?", + (state_group, room_id,) + ) + prev_group, = txn.fetchone() + new_last_state_group = state_group + + if prev_group: + potential_hops = self._count_state_group_hops_txn( + txn, prev_group + ) + if potential_hops >= MAX_STATE_DELTA_HOPS: + # We want to ensure chains are at most this long,# + # otherwise read performance degrades. + continue + + prev_state = self._get_state_groups_from_groups_txn( + txn, [prev_group], types=None + ) + prev_state = prev_state[prev_group] + + curr_state = self._get_state_groups_from_groups_txn( + txn, [state_group], types=None + ) + curr_state = curr_state[state_group] + + if not set(prev_state.keys()) - set(curr_state.keys()): + # We can only do a delta if the current has a strict super set + # of keys + + delta_state = { + key: value for key, value in curr_state.items() + if prev_state.get(key, None) != value + } + + self._simple_delete_txn( + txn, + table="state_group_edges", + keyvalues={ + "state_group": state_group, + } + ) + + self._simple_insert_txn( + txn, + table="state_group_edges", + values={ + "state_group": state_group, + "prev_state_group": prev_group, + } + ) + + self._simple_delete_txn( + txn, + table="state_groups_state", + keyvalues={ + "state_group": state_group, + } + ) + + self._simple_insert_many_txn( + txn, + table="state_groups_state", + values=[ + { + "state_group": state_group, + "room_id": room_id, + "type": key[0], + "state_key": key[1], + "event_id": state_id, + } + for key, state_id in delta_state.items() + ], + ) + + progress = { + "last_state_group": state_group, + "rows_inserted": rows_inserted + batch_size, + "max_group": max_group, + } + + self._background_update_progress_txn( + txn, self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME, progress + ) + + return False, batch_size + + finished, result = yield self.runInteraction( + self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME, reindex_txn + ) + + if finished: + yield self._end_background_update(self.STATE_GROUP_DEDUPLICATION_UPDATE_NAME) + + defer.returnValue(result * BATCH_SIZE_SCALE_FACTOR)